Percentages Part A

First of all I have to apologize to my readers for my late post. This will not happen again, at least I hope so. Today I am going to lecture on percentages. Percentages are a very common topic in Mathematics and especially on the S.A.T. In the S.A.T, percentages come in some of the forms I have provided below.

The first form is given by this example. 30% of x is 27, what is x? This is the simplest form, and it usually comes in the first ten questions of a Mathematics section. A similar form is; if 60%y is 120, what is 75% of y?

Another form comes in the form of a worded problem. These are a little tricky especially the wording of problems referring to depreciation/appreciation. Now I will give you a depreciation question but I will not show you how to solve it in this post. When I am doing appreciation/depreciation, which is my next post, I will refer to this very question! This is the question.

A house of value $500,000 depreciates annually by 2%. What will be the new value of the house 5 years from now, starting January 1st, 2008? This is a medium level question and it occurs between questions 15 and 20. Do not underestimate the power of this question, it between questions 15 and 20 for a specific reason.

The last example is very common on the S.A.T and is the most difficult questions pertaining to percentages and is found in the last five questions of the Mathematics sections. They come in the form of only letters and percentages, but then again it will be easy for you, so do not be intimidated by these questions!

60% of x is 30% of y. if w = 4x, what percentage is (x + y)/w?

a) 15%
b) 25%
c) 60%
d) 74%
e) cannot be determined from the information above

In my next post I am going to show you how to solve these questions and also my mind method of solving these questions of solving these questions.